Guarantee durable visible runtime logging

README.md

@@ -23,7 +23,7 @@ WinForms tool for controlled Microsoft BizTalk Server 2020 platform operations d
 - Dry-run mode enabled by default
 - WMI access through `root\MicrosoftBizTalkServer`
 - Startup check for administrator rights
-- Detailed operation logging in the GUI and daily rolling log files under ProgramData
+- Detailed operation logging in the GUI and daily rolling log files in a write-verified local directory
 - Automatic operation-log restoration into the grid after an application restart
 - Thirty-day runtime-log retention with GZip compression for completed daily logs
 - Process-local ScheduledTask adapter dependency resolution for `scheduler:` receive locations without modifying the GAC
@@ -83,9 +83,13 @@ Orchestrations that were `Bound` are deliberately left unchanged during restore
 - Timestamped `emergency-source-before-*`, `emergency-restore-plan-*`, `emergency-restore-result-*`, `emergency-restore-after-*` and `emergency-restore-diff-*` files
 - `diff.json`, `diff.csv`, `diff.html`
 - Snapshot sidecars: `*.csv`, `*.hosts.csv`, `*.html`
-- Runtime logs under `%ProgramData%\BizTalkPlatformManagementTool\Logs`
+- Runtime logs primarily under `%ProgramData%\BizTalkPlatformManagementTool\Logs`
 
-The current day remains a plain `BizTalkPlatformManagementTool-yyyy-MM-dd.log`. Completed daily logs are compressed to `.log.gz`; the current day plus the previous 29 calendar days are retained. Older records are removed on startup. Up to the newest 10,000 retained entries are automatically restored from plain and compressed files into the Operation Log grid after a restart. If ProgramData is unexpectedly unavailable, logging falls back to the executable directory.
+The current day remains a plain `BizTalkPlatformManagementTool-yyyy-MM-dd.log`. Completed daily logs are compressed to `.log.gz`; the current day plus the previous 29 calendar days are retained. Older records are removed on startup. Up to the newest 10,000 retained entries are automatically restored from plain and compressed files into the Operation Log grid after a restart.
+
+At every start, the application performs an actual create/write/flush/delete probe and then appends a visible startup verification record. The ordered locations are ProgramData, the current account's LocalAppData, `Logs` below the executable directory, and Temp. **Log Folder** opens the path that really accepted the write. A fallback or complete storage failure is shown with attempted paths and exception details in the Operation Log; it is never silently ignored.
+
+`C:\Program Files\BizTalkPlatformManagementTool` therefore normally contains no log file. ProgramData is a separate, normally hidden Windows directory. An install-local `Logs` subdirectory appears only when both ProgramData and LocalAppData were rejected and Program Files itself permits the fallback write.
 
 ## Troubleshooting
 
@@ -97,6 +101,8 @@ For a ScheduledTask receive location, the operation plan retains adapter name an
 
 Error records in the grid, execution report and file log include exception type, HRESULT, complete inner-exception chain, available Fusion loader information and stack trace. For the PROD validation and support bundle, follow [ScheduledTask control and runtime logging runbook](docs/PROD-ScheduledTask-und-Laufzeitlogging-2026-08-26.md).
 
+For the specific PROD finding "no logs visible below Program Files" and the version 2.3.1 storage verification, follow [PROD runtime-log storage validation](docs/PROD-Laufzeitlog-Ablage-2026-08-26.md).
+
 Snapshot and plan JSON files are written as UTF-8 without BOM. Loading is tolerant of existing files that contain a UTF-8 BOM or a visible BOM marker from previous encoding conversions.
 
 JSON snapshots and plans are written through a same-directory temporary file and atomic replacement. Snapshot comparison keys artifacts by application plus name, preventing collisions between equal artifact names in different applications. CSV fields that could be interpreted as spreadsheet formulas are neutralized.
@@ -127,5 +133,6 @@ Targeted German inline comments explain non-obvious operational decisions such a
 - [Optional all-users desktop shortcut stability](docs/Installer-Optionale-Desktopverknuepfung-2026-08-24.md)
 - [ACC runtime shutdown incident and recovery fix](docs/ACC-Runtime-Shutdown-Exception-2026-08-19.md)
 - [PROD ScheduledTask control and runtime logging runbook](docs/PROD-ScheduledTask-und-Laufzeitlogging-2026-08-26.md)
+- [PROD runtime-log storage validation and 2.3.1 fix](docs/PROD-Laufzeitlog-Ablage-2026-08-26.md)
 - [AI maintainer handoff](AI-README.md)
 - [References](REFERENCES.md)